I would look at the family care plan policies and determine if any might be applicable to the situation. A Soldier seeking sole guardianship might be required to have one (outside my area of expertise), and will certainly need one if full custody is granted.
Second, there are certain legal protections for deployed soldiers that the soldier and his attorney should be aware of. Simply put, you can't make judgements on troops who are unavailable due to military orders. Contact your servicing JAG for specifics.